The aim of this work is to develop, improve and operate a domestic anaerobic digester as an open hardware apparatus to promote decentralized energy and nutrient recovery. A brief introduction to the concept of decentralized energy and nutrient recovery is presented and its connection to the Water-Food-Energy Nexus, which claims citizen participation in the process is highlighted. The construction and use of an Open Hardware anaerobic biodigester named Boitatá was based on communities of interest, so as to permit its replication in hackerspaces, fablabs, etc. The developed reactor was tested in real life conditions for a family of three people and their pets, and some improvements were proposed and implemented to make it easier to build and operate. During the field testing period it has managed to treat all the organic waste daily generated in the household (around 800 g) with a specific biogas production of around 0,710 Lbiogas/gSV, which covers about 21% of the family cooking energy demand, demonstrating the viability of the apparatus for the descentralized anaerobic digestion in urban households and small enterprises.

The design of systems for energy recovery of municipal solid wastes (MSW) requires the knowledge of its properties, among which, the heating value stands out. The obtaining of reliable data is related to sampling process, that must be based on statistical principles, and due to MSW heterogeneity, it results in the analysis of many samples, which leads to high costs. In this sense, this work proposed a method of samples composition for the experimental determination of chemical properties of MSW fuel categories (organic, sanitary, plastics, textiles, and paper) with the intention of reduce the number of laboratorial analyses, maintaining the statistical level of confidence. The results were compared with those obtained with the complete set of samples. Empirical models to predict the LHV of MSW from their ultimate or gravimetric composition were also evaluated. Fuel categories samples were composed by a mixture of individual samples obtained from 36 garbage collector vehicles of mixed collection in the municipality of Santo André (state of São Paulo, Brazil), considering its representativeness on the gravimetric composition of each vehicle. The LHV, ultimate and proximate compositions were experimentally determined. The results were satisfactory, showing low deviation (MAPE between 5% and 11%) when compared with those obtained from the set of individual samples. The composition of a single sample, representative of the local MSW, also showed a good result (MAPE of 16%), but more analyses are indicated to validate it. The proposed methodology allowed to reduce by more than 97% the number of analyses. The deviations between the LHV obtained by using empirical and experimental models ranged from 52% to 0%. Models based on physical composition showed acceptable deviations for the prediction of LHV from a composite sample representative of MSWfuel.

O crescente número de resíduos sólidos urbanos nas cidades, estão resultando em grandes problemas para as administrações públicas. Atualmente cerca de 58% dos resíduos coletados no Brasil são enviados para aterros sanitários, e 42% são destinados a locais inadequados. O problema não está relacionado somente com área apropriada para o depósito desses resíduos, mas com a produção natural de metano, gás muito mais prejudicial ao meio ambiente do que o próprio dióxido de carbono, porém com alto poder calorífico. Este trabalho buscou construir, através de métodos de análise estatística, um modelo que possibilite prever a produção de biogás em um aterro sanitário. Foram realizadas simulações, utilizando-se de parâmetros da literatura, que possuem características de distribuições gaussianas. De acordo com as simulações, foi possível projetar um modelo hipotético que leva em consideração as variabilidades que ocorrem com os resíduos depositado em um aterro sanitário.

O tratamento e destinação dos resíduos sólidos urbanos é um problema socioeconômico e ambiental. Mais da metade dos resíduos coletados são constituídos de matéria orgânica e, uma vez dispostos no ambiente de forma inadequada, se decompõem naturalmente, contaminando a água, o solo e o ar. A degradação da matéria orgânica em ausência de oxigênio produz metano e gás carbônico, gases geradores de efeito estufa que contribuem para as mudanças climáticas. Os aterros sanitários são considerados pela legislação vigente a forma mais adequada de destinação final destes resíduos. São pontos positivos: gerar energia nos aterros sanitários, a utilização dessa energia para seu próprio funcionamento, ou distribuir na rede a energia para beneficiamento local. Neste trabalho, foi feita uma avaliação da produção de biogás associado à decomposição da fração orgânica dos resíduos sólidos urbanos nos aterros sanitários do Brasil que utilizam esse tipo de energia para seu próprio consumo ou que a injetam na rede de distribuição. Os impactos ambientais, econômicos e sociais associados a localização dos aterros também foram avaliados. Um modelo sistêmico foi obtido para definir os parâmetros de causa e efeito que giram em torno do tema. Os indicadores mais importantes foram selecionados para compor a matriz de sustentabilidade. Com o software QGIS foi possível analisar a localização, constatando-se que todos pertencem à região Sudeste do país.

A Política Nacional de Resíduos Sólidos (PNRS) do Brasil objetiva promover a gestão integrada e o gerenciamento dos resíduos sólidos, de modo a assegurar um destino final ambientalmente adequado. A disposição dos resíduos sólidos domiciliares (RSD) é um desafio na maior parte dos municípios brasileiros, muitas vezes efetuada sem tratamento prévio, com inúmeros impactos ambientais negativos. Nesse contexto, o objetivo deste estudo foi analisar o potencial energético dos RSD do Brasil, a partir do atual cenário do gerenciamento desses resíduos. O estudo foi feito a partir da estimativa do potencial energético das principais frações combustíveis que compõem os RSD brasileiros, combinando-se informações obtidas da literatura. A fração mais significativa é de matéria orgânica, seguida de recicláveis e por fim rejeitos, com cerca de 51%, 35%, e 14% respectivamente. Com intuito de mostrar os benefícios econômicos e ambientais que esse tipo de resíduo apresenta como recurso, o tratamento é uma alternativa para a demanda de energia que a cada dia aumenta, como solução já que os recursos naturais tendem a esgotar.

: Brazil is the world’s largest producer and consumer of passion fruit, being a tropical fruit that produces a lot of waste in its process. As this residue is more than 60% of the mass of the fruit, there is a problem directed to the discard of the same. One way to add economic and financial value to the passion fruit industry would be to use the waste as a source of fuel in a process of converting biomass to energy. The objective of this work was to characterize samples of passion fruit residues by analyzing the moisture content and the experimental calorific value, aiming at its energy utilization, in order to obtain initial information to help define the best conversion path of this biomass: thermochemical or biochemical. After analysis, it was concluded that the most appropriate biomass utilization route would be anaerobic biodigestion due to the high moisture content presented in the samples (greater than 80%). However, the same ones, if in dry basis, also have high calorific value, compared, for example, with sugarcane bagasse. With the results, it was demonstrated that the biomass of the passion fruit pulp presents itself as a potential alternative for the energy utilization.

Currently, one of the major problems faced by managers of solid urban waste is the final disposal of the waste generated by their population. Waste disposals should be done in spaces and/or under appropriate conditions, in order to minimize socioeconomic and environmental impacts. In this context, this article aims at estimating the energy recovery potential of urban solid waste using mathematical simulation models for anaerobic biodigestion and incineration. As object of study, the waste disposed in Caieiras landfill, located in the city of Caieiras/SP, was considered. To evaluate the anaerobic digestion, mathematical models were used to estimate methane production as function of the various factors that influence the process (acetate and microorganisms concentration, pH variation among others). In the case of incineration, empirical mathematical models (based on immediate, gravimetric and elementary analysis) were used to estimate the lower heating value of urban solid waste. According to the results obtained, it would be possible to obtain an average power of 38.8 MW for anaerobic digestion. If the incineration method was adopted, it would be possible to obtain an average electrical power of 214 MW (considering the total incineration of the waste). Based on the simulations carried out for anaerobic biodigestion and incineration as possible methods of municipal solid waste disposal, it is concluded that the incineration process of municipal solid waste presents a greater potential of electricity generation, approximately five times higher than the energy conversion potential of anaerobic digestion.

RESUMO Atualmente, um dos grandes problemas enfrentados pelos gestores de resíduos sólidos urbanos (RSU) é a disposição final dos resíduos gerados por sua população. As disposições de resíduos devem ser feitas em espaços e sob condições adequados de modo a minimizar os impactos socioeconômicos e ambientais. Nesse contexto, este artigo teve por objetivo estimar o potencial de recuperação energética de RSU usando modelos de simulação matemática para a biodigestão anaeróbia e a incineração. Como objeto de estudo, foram considerados os resíduos dispostos no aterro sanitário de Caieiras, localizado no município de Caieiras (SP). Para avaliação da biodigestão anaeróbia, foram analisados modelos matemáticos que permitem estimar a produção de metano em função dos diversos fatores que interferem no processo (concentração de acetato e de micro-organismos, variação do pH, entre outros). No caso da incineração, foram considerados modelos matemáticos empíricos (baseados nas análises imediata, gravimétrica e elementar) para estimar o poder calorífico inferior dos RSU. De acordo com os resultados obtidos, para a biodigestão anaeróbia seria possível obter potência média de 38,8 MW. Caso a incineração fosse adotada como método de tratamento dos RSU, seria possível obter potência elétrica média de 214 MW (considerando a incineração de 100% dos resíduos). Com base nas simulações realizadas para a biodigestão anaeróbia e a incineração como possíveis métodos de destinação dos RSU, conclui-se que o processo de incineração apresenta potencial de geração de eletricidade aproximadamente cinco vezes maior do que a conversão energética da biodigestão anaeróbia.

Municipal solid waste (MSW) management is a serious problem for public administrations, especially in terms of treatment and final disposal. These wastes have a high energy content and one of the possibilities of treatment is the recovery of energy through thermochemical processes. The parameter used to measure the amount of useful energy available in collected waste when submitted to thermochemical processes is called the lower heating value (LHV), which is usually determined in the laboratory or through empirical models from the literature. To this end, this paper aims to present two models for prediction of the LHV in the municipal solid waste of the municipality of Santo Andre. Samples were collected from 36 garbage trucks in the above-mentioned city, from September 2015 to January 2016. The models were developed based on the results of the gravimetric composition and laboratory analysis. The technique used to develop the models was the multiple linear regression by least squares method. As a result, the models obtained mean absolute percentage error (MAPE) indexes of 5.09% and 5.52%, considered excellent according to the literature classification. In addition, the calculated LHV of the Santo Andre municipal waste was 7.03 MJ/kg, which indicates a great potential for energy recovery using thermochemical processes. These are the first LHV prediction models developed in Brazil, which has been a significant accomplishment in Brazil. The proposed models were developed using empirical measurements of moisture in the solid waste and the LHV on samples collected with a statistically representative sampling method. (C) 2019 Elsevier Ltd. All rights reserved.

This article deals with the challenges and obstacles facing the management of Urban Solid Waste (MSW) in the municipalities of ABC Paulista. In compliance with the guidelines imposed by the National Solid Waste Policy 12,305/2010, which determined that the entire city has a duty to create the PMGRS (Municipal Solid Waste Management Plan), and the creation of measures for constant changes in the collection of municipal waste and in the treatment and disposal of MSW. The objective of this article is to identify the level of sustainability in solid waste management in the following municipalities: Santo André, São Bernardo and São Caetano do Sul. The methodology used in this article was divided into three parts, the first part being the collection of primary and secondary data, the second was the integrated diagnosis of the results and, finally, the future prospects in relation to a proposal for new scenarios for the municipalities studied. The municipalities presented different results, and some positive aspects, the municipality of Santo André has excelled in most of the scenarios, even with all the presented obstacles.

The growth of the world population triggers the increase of production of solid waste. In Brazil, the situation is even more serious, because, besides the fact that the Brazilian population produces a high quantity of waste, the final destination for them is inappropriate. In this context, energy recovery by thermochemical processes can be a good option, reducing the waste volume for final disposal and recovering useful energy. The adequate design and operation of a waste incineration plant requires the prediction of the amount of energy that can be obtained from the waste used as fuel. Several models for predicting the heating value of MSW have been developed. This paper presents a prediction model for the Lower Heating Value (LHV) of the Municipal Solid Waste (MSW) from the city of Santo Andre, based on experimental data using multivariate regression. The model proposed presents a deviation of 1,77% and a MAPE index of 6,48%.

Waste-to-Energy (WtE) processes are widely used to convert solid waste into energy. A WtE plant can contribute to diversify the energy mix and increment the energy supply security of a country. Predict the amount of energy - the heating value - that can be obtained from the waste used as fuel is necessary for the proper operation of a WtE plant. Work with MSW, both in the landfill as in the laboratory, is an unhealthy activity, and requires skilled labour and specialized equipment, usually with a high cost, which cannot be afforded by undeveloped countries. Usually, waste heating value forecasting models are used to minimize the experimental work and, in this sense, it is important to know which techniques can produce good models with a minimum amount of samples. In this paper, three different techniques were compared: Multivariate Linear Regression (MLR), MultilayerPerceptron Artificial Neural Network (ANN), andExtreme Learning Machine (ELM). 36 data samples were available; 26 samples were used as modelling data and 10 samples were used as validate data. As a result, both MLR and ELM techniques had good indexes, with a slight advantage to the ELM, with aMAPE of 4.84% and a MSEof 0.965.

Solid Waste production is a problem it has intensified over the years. The environment protection, that pollution and sanitation availability is a civil right, according to Federal Constitution, so the government must be responsible for environmental control practices. The Solid Waste National Plan is a document drawn up from the Solid Waste National Policy that strengthens the principles of integrated and sustainable waste management, it proposes measures to promote the collection, treatment and disposal of solid waste. This study presents an overview of Municipal Solid Waste of Santo Andre in Brazil, in order to characterize the organic fraction using the chemical composition to evaluate the possibility of energy recovery treatment by biochemical process of anaerobic digestion. To this end, it was determined the chemical characteristics of the organic fraction of MSW disposed in the Municipal Landfill of Santo Andre such as lipids and protein composition. It was studied the household and commercial waste sources, the CRAISA (Regional Integrated Supply Company of St. Andrew) and fairs. Some results were compared and interrelated. Average values form: The 5.43% lipid content +/- 0.51% for the routes of wet waste, 2.31% +/- 0.44% for CRAISA and 3.24% +/- 0.23% for for open-market; the protein content was 12.23% +/- 2.10% for the routes of wet waste, 8.75% +/- 0.44% for CRAISA and 9.69% +/- 1.17% for open-market, standing therefore in the excellent results for the process of anaerobic digestion occurs.

Wastes can become a profit if they are transformed into raw materials for other processes, such as the case of biomasses, which are aimed at energy conversion. The Brazil has a very considerable production of the fruits of acai berry (Euterpe oleracea) and coconut (Cocos nucifera). In 2015, the extraction of the fruits of these two palm trees reached 216,071 and 1,958,663 tons, respectively. The acai berry seed represents 83% of the fruit and the coconut shell represents 57% of the total weight of the coconut, so the amount of residues generated in this extraction is very large. Due to these facts, this study aims to characterize the biomass of acai berry seeds and coconut shell to be designed to thermochemical processes for converting energy. The biomasses were collected in the Amazon region and characterized by means of the immediate, elementary and calorific analysis to know their energy potential. It was seen that both biomasses have volatile material higher than 76% and low ash content. HHV was above 17 MJ/kg, being comparable to HHV of sugarcane bagasse, one of the most used biomasses in Brazil for energy purposes, thus showing its potential for thermochemical processes.

The physical and thermal properties of briquettes composed by straw, bagasse and vinasse as residues from sugarcane industry were determined by varying the proportions according to central compose experimental design 2(3) with three central points, considering temperature, moisture and the percentage of bagasse composition in the briquettes as independent variables. The characterization was performed according to the proximate and ultimate analysis in order to quantify the components in these residues. It was also determined the superior and lower heating value in order to allow the determination of energy potential. The effect of processes parameters on the briquettes properties was evaluated according to the mechanical performance and the energetic density. It was observed that temperature presented a positive effect on mechanical resistance and energetic density. Both, energy potential and the mechanical properties of bagasse, straw and vinasse briquettes are favored by the set of physicochemical properties, which improves when the residues interacting. The best processing conditions of the briquettes are present in the average level, considering that also the low moisture, presence of straw in the composition and the agglomeration produced by the solids present in the vinasse are also favorable.

Municipal Solid Wastes (MSW) are considered as residual biomass. Its energy recovery is one of the possibilities of adequate destination foreseen by the brazilian National Solid Waste Policy (NSWP - Federal Law 10304, 2010). Considering the environmental and social issues associated with waste generation and management, appropriate solutions for this problem must take into account not only technological aspects, but also the educational dimension. The lack of environmental awareness is one of the greatest difficulties in the implementation of new technologies for waste treatment. In view of the above, this project aims to enhance environmental education related to MSW in the ABC region (Sao Paulo / Brazil). The target audience is both the internal community of the Federal University of ABC and the whole community of citizens of the ABC region. The actions of this project are methodologically based on the review of specialized literature, field research, photographic records, statistical data collection, application of evaluation questionnaires and the exchange of experiences with other experts. This work presents the preliminary results of the diagnostic phase, in which data related to environmental education at the main municipalities of the ABC region were collected in order to identify the environmental consciousness of the target audience related to the generation and appropriate destination of MSW. Through actions of environmental education conducted by UFABC, it is intended to strengthen the effectiveness of the municipal governments programs, aiming to awaken a more ethical and responsible consciousness in citizens practices with respect to the waste problem in the ABC of Sao Paulo/Brazil.

Nesse trabalho, objetivou-se avaliar a producao de biogas durante o processo de biodigestao anaerobia de dejetos de bovinos leiteiros, com e sem a separacao de solidos. Utilizaram-se 16 biodigestores do tipo batelada, com volume util de 2L, abastecidos com dejetos obtidos em 4 diferentes condicoes: (1) o dejeto in natura apos a lavagem dos pisos dos estabulos; (2) apos o separador de solidos; (3) apos o separador de solidos e um decantador de areia e (4) com o dejeto solido retido no separador de solidos diluido em agua. O tempo de retencao hidraulica foi de 196 dias. As maiores reducoes de solidos volateis (SV) foram obtidas para os biodigestores abastecidos com os dejetos que passaram por algum processo de separacao de solidos e o maior potencial de producao de metano (CH4) foi de 0,2686 m³ de CH4 kg-1 de SV adicionados para os biodigestores abastecidos com os dejetos apos o separador de solidos. Observaram-se melhores potenciais de producao de biogas e metano quando ocorre uma reducao na concentracao de solidos nos dejetos e, nesse caso, os tempos de retencao hidraulica podem ser reduzidos, o que reduz o volume do biodigestor e custos de implantacao e de manutencao, porem as maiores producoes de biogas ocorreram nos biodigestores sem a separacao de solidos.

The plastic fraction contained in the wet residues of the Santo Andre is about 14.6% being composed, in large part, for non-recyclable waste due to its contamination. The main goal of this work is to compare three different methodologies used to perform the immediate analysis of the fraction of plastics contained in the wet residues, in order to verify if there will be divergences between the values. After preparation, the samples were submitted to the immediate analysis following the Standard Methods with different methodologies. Regarding the analysis of volatile material, the values obtained do not show big differences between each other, with an average value of 90.1% and 87.8%. As for the ash content analysis, the value found was 7.5%. As for the sequential method, the value is much higher than expected (24.2%). For the results obtained from the macro-TGA analysis the values were close to those obtained by ASTM by the individual methodology. The values obtained by macro-TGA confirm that when using the ASTM method with the individual methodology it is possible to obtain more representative values while, when using the sequenced methodology the values are also not compatible with the values obtained by macro-TGA and in literature.

Nos equipamentos de conversao energetica, os processos de formacao de escoria ( slagging ) sao associados com a sinterizacao e fusao das particulas das cinzas nas superficies internas da fornalha a temperaturas elevadas, o que degrada o seu desempenho e danifica severamente os equipamentos que constituem o sistema de combustao. O objetivo deste trabalho foi estimar os indices de formacao de escoria das fracoes combustiveis presentes no fluxo de Residuos Solidos Urbanos (RSU) umidos a partir da analise de 20 veiculos de coleta, do municipio de Santo Andre S.P., avaliados entre as estacoes primavera de 2015 e inicio do verao de 2016. Cada veiculo foi oriundo de um subsetor diferente do municipio. Foram determinados o poder calorifico superior (PCS) e os teores de cinzas, para cada uma das fracoes combustiveis (materia orgânica, residuos sanitarios, plasticos, papel/papelao/tetra pak® e texteis). A partir da analise dos resultados observou-se que a categoria de materia orgânica apresentou o menor valor medio de PCS (16,36 ± 2,98 MJ/kg), maior valor do teor de cinzas (22,48±11,56%) e maior valor de indice de formacao de escoria (IA) (2,80± 7,27 kg de alcalis/GJ) dentro das categorias combustiveis avaliadas. A categoria de plasticos, por sua vez, apresentou o maior valor de PCS (33,41± 2,40 MJ/kg), um dos menores teores de cinzas (6,67± 3,16%) e o menor valor de IA (0,41± 2,78 27 kg de alcalis/GJ). As demais categorias apresentaram valores de IA superiores a 0,34 kg de alcalis/GJ, o que denota o risco de formacao de escorias. Desta forma e possivel inferir que as categorias combustiveis avaliadas neste trabalho apresentam riscos de formacao de escorias ressaltando-se a categoria de materia orgânica, ja que devido a suas caracteristicas combustiveis apresenta certezas de formacao de escorias em processos de conversao termoquimicos (incineracao). Palavras chave: RSU, escoria, incineracao, cinzas.